The CGS says planners use them to ensure homes and buildings aren't built right on top of California’s known active faults. The maps are also used in real estate transactions as part of the disclosure packet.

"California is earthquake country," Dr. John Parrish. "If people are purchasing property, they need to know whether they’re in an Earthquake Fault Zone, and thus are in an area of increased risk to surface fault rupture. Using this tool, they can find out whether they’re in a community that has been zoned. If not, they don’t have to think about it anymore. If they are in a zoned city or county, then they can take a closer look at the maps."

The scientists will talk about what they show during a Thursday news conference in Sacramento.

Remembering Loma Prieta 23 Years Later

When it comes to the most populated areas, there are only a few random neighborhoods that appear to be in a safe zone. They are around Campbell and South San Jose and one just north of Sunnyvale near Moffett Field. And it's worth noting that the entire city of San Francisco appears to be in the clear